Refrigerating apparatus



Aug. 27', 1929. R. w. DAVENPORT A REFRIGERATING APPAR'ATUS Filed April29. 1926v 2 sheets-sheet 1 Y girlz Y A TTORNE Y.

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Aug. 27, 1929. R. w. DAvlw-:NPORT t l REFRIGERATING APPARATUS FiledApril 29, 1926 2 sheets-sheet 2 www 4//,

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Patented thug. 27, 1929.

UNITI-:o STATES PATENT o-F'Flfcr.. l

BANBOM W. DAmBT, 0l' DI'OIT, MICHIGAN, `.ASSIGNDB' CHICAGO m11- HATICT0012 00mm, Ol'mvYOBx, H., Y., A. CORPORATION 0l NEW mBIGmTIlG APPARATB.

' Application led April 89, 1888. Serial lo. 105,872.

This invention relates to apparatus for producing thermodynamic effectsand in particular to apparatus Ifor use in connection with refrigcratingand freezingcabinets and compartments! While it possesses many featuresof general application ithas a special field in mechanical refrigeratinoutfits for househ'o`ld use where features ofgcompactness, simplicity,elliciency and economy are particularly desired. In refrigerativ systems'elements functioning to absorb eat 'from the medium in contact with onesurface through the evav ration of a suitable medium in contact with theopposite surface are old and commonly used in forms adapted for variousspecific applications. When the contact medium from which hea-t .isabsorbed is the atmosphere, it

is common practice to extend lthe contact area by various expedientssuch as fins,`corru tions, tubes, coils, etc. as it is well known t at'a given quantity of heat can be absorbed from air with less temperaturedifferences between; the air and the element when the contact area islarge than when it is .relatively small. Commonly used structuresgenerally afford relatively great air contact surface packed in'- rtorelatively small cubical volume. For instance, the elements used indomestic refrigeration are in the form of coils and headers, or cubicaltanks occupyin and fillin the space which, before the a vent of sucimprovements, was filled with ice.

The elements just described are always operated' at temperatures colderthan melting ice and act to induce va rather rapid circulation of arelatively small proportion of the air content of the entirerefrigerator, so that the current of air leaves the element attemperatures far below ythe average temperature 'of the refrigerator.Therefore, there is valways a great difference between the temperatureof the element and that ofthe articles in the re.-4

frigerator. With the conventional arrange-v ment of the refrigeratingelement in a corner o'f the refrigerator, often isolated by partitions,radiation from warmer objects to such an element is o f course quitenegligible, since few or none of them can see it.

It is an object of the present invention to provide a refrigeratingelement adapted to cause a rather slow circulation of a relatively largeproportion of the air content of the compartment or refrigerator to becooled and so formed and disposed as to be seen by all or most of theob'ects in the refrigerator so as to take some of t eir heat byradlation in addition to the convective transfer by way of the i Ycirculated air. Another object is to provide a refrigerator havin themaximum food storage capacity with t e least possible volume lost in therefrigerating elementused therewith. Another object is to establish andmaintain a more even and more uniform temperature throughout the foodstorage space.,

.Another object is to provide a freezing element having improved heatabsorbing effects upon objects placed within it. A still further objectis to. attain the above objects with forms of apparatus which are cheaplmanu-` factured and of simplified constructlon.

It is well known in other arts that the temperatures within a nearlytotal enclosure tend to reach perfect equality, and such nearly totalenclosure is sometimes called a"black body because it radiates through asmall opening inA its wall the 'maximum amount of heat, as does asurface covered with lamp black. My invention further aims to secure 'inheat absorbing devices, results similar to the effects noted 1n blackbody structures. y In carrying out my' invention I provide both a largesurface contact area and a near- Vly total enclosure by the novelcombination Fig` 3 is a view similar to Fig. 2 showing a different formof refrigeratingelement. v

Fig. 4r is a view similar to Fig. 1 showing still another form ofrefrigeratin element.

Fig. 5 is a horizontal section view substantially 'on the line 5-5 ofEig. 4.

to 4 inclusive, substantially on the line 7 7' of Fig. 8.

Fig 8 is a longitudinal, vertical, sectional vlew on the line 8-8 ofFig. 7.

Fig. 1 illustrates the invention as embodied in a mechanicalrefrigerating outfit for household use comprising a refrigerator Ahaving.

its lower part provided with a chamber in whlch are dlsposed themechanical parts of the refrigerating apparatus which may include a pumpor compressor B and a prime mover for drlving the compressor, such as anelectric motor C. Above the apparatus chamber are disposed thecompartments from which heat is to be extracted. In the p1 esentinstance two compartments are shown, namely, a freezing compartment D inwhich liquids are intende to be frozen and a food storage compartment E.The freezing compartment D contains a freezing element al and the foodstcrage compartment E arefrigerating'elemente. These elements serve ascontainers or evaporators for the refrigerant fluid and are connected inseries by a suitable duct f. The vaporized refrigerant is drawn from thetop of element e through connection g -which leads to the inlet of pumpB and the discharge of the pump passes through pipe la into a condenser(not shown) and thence into element d, a suitable throttling orexpansion device i being interposed to'control the rate of feed of thecondensed refrigerant.

The invention relates especially to the form, extent, disposition andarrangement of Ythe refrigeratinfg elements utilized to extract heatfrom the reezing compartment D and the food storage compartment E.. Inorder to attain thedesired simplicity and compactness as wellas tosecure the greatestconserva-` tion of space for useful refrigeratingpurposes the refrigerating elements are preferably constructed so as toenable them to form at least a portion of tlie lining of thecompartments in which they are disposed. The element for the foodstorage compartment will first bc considered since it may conform to ordiffer from the preferred structure of the freezing element withoutdeparting from the 'objects of the invention. The element 4may beconstructed in a variety of ways and utilized to line any desired partof its compartment. Typical forms and arrangements only are herein shownand described. The type of refrigerating element e disclosed in Figs. 1and 2 is arran ed to form the lining for the back and top of the foodstorage compartment E and comprises a long metal pipe or-tube 9 coiledor disposed in substantially horlzontal parallel stretches and securedto a metal plate or sheet 9l with which the coil has good thermalcontact so that plate 9a forming the lining of the back and top of thecompartment acts as an elicient heat absorber.

Fig. 3, discloses a slightly different' form of refrigerating element ewhich, however, lines the same 'parts 'of the food storage chamber asdoes the element disclosed in Figs. 1 and 2, namely, the back and topthereof. This evaporator comprises two metal plates 10 and 10a disposedin4 face engagement and united in a fluid-tight manner at theirperipheries to form therebetween a chamberpof restricted volume for thevaporizing refrigerant. Element e is constructed of the proper size andwith a right angle bend at 10b sofas to closely lit the rear and topwalls of chamber E and form a part of the lining of the compartment.Element e has an inlet connection 10c at its base leading from freezingelement d and at its top an outlet 10dl for connection with thecompressor.

Figs. 4 and 5 disclose still another arrangement of a refrigeratingelement in the food storage space E. This element e2 is similar instructure to that disclosed in Fig. 3 being formed of two sheet metalplates 10 and 10 disposedA in face engagement and peripherally united.This element, however, has two right angular bends at 10 and 10,respectively, and

is formed of such proportions as to lit and to line three sides ofcompartment E, namely,

the back and the two sides. The chamber for refrigerant provided byrefrigerating ele-` ment e2 is enlarged somewhat adjacent the top andbottom of the element in any suitable manner as by outwardly bulgingeither or both of the plates 10 and 10a in a substantially wood, metal,or other suitable material, and

a layer of the heat insulating material a forming a relative thick wallwithin casing a. Immediately adjacent the insulating `Wall a is disposedthe refrigerating element, elther e, e or e2. Fig. 6 happens toillustrate the form of element shown `in Figs. 3-5. To

maintain the plates 10 and'l()a forming the refrigerating element e ore2, slightly apart, so as to form a chamber of small but fixed volumefor the refrigerant fluidi, suitable means are provided. Such meanspreferably take the -form of interior projections upon one or both ofthe plates. Inthe present 1nstance, the rear plate l() has been dented'at intervals to form projections 10t to engage the inner face lof plate10a. AWhile plate 10,

which forms a part of the lining of compartment E, may be wavy orcorrugated to resent a great air contact area instead of p ain andsmooth as shown it should be in such form as to be easily kept in aclean and sanitary condition.

From the above it will be apparent that even if the refrigeratingelement used to line the chamber from which heat is to be extracted ismade of a thick heavy material so as to withstand successfully highpressures or the impact of heavy objects which might be stored in thechamber, the necessa contact area for heat removal to maintain or inaryrefrigerating temperatures can be secured with an extended refrigeratingelement occup 'ng not more than ten per cent of the cubica volume of thecompartment. When conditions safely permit the use of thin walled sheetmetal refrigerating elements of the type disclosed in Figs. 3 to 6 as ininstallations operating in accordance with the process disclosed in mycopending application, Serial No. 15,- 172, filed March 12, 1925, thespace occupied by the element is reduced to approximately 312 of thevolume of the compartment, a quite insignificant amount in view of theextension of the element. i

By using the refrigerating clement to line the storage compartment,after the manner disclosed in Figs. 1,-5, an important ad- ,vantageadditional to that of the increased space available for useful purposesis secured. This advantage lies in the fact that almost every objectplacedin the compartment can see atleast a portion of the element sothat heat is withdrawn from the objects by radiation as well as byconvection.

Figs. 7 and 8 illustrate a preferred embodiment of the inventionparticularly adapted for freezing compartments although equallyavailable for compartments intended to onerate at a higher temperature,if desired. This element provides an almost total enclosure in whichheat is extracted from at least four walls thereof, namely, top, bottomand sides. The structure of the walls conforms substantially to thatofthe type of element disclosed in Figs.l 3-5.' The element-.d consistsof a double Walled enclosure having a lining formed by a metal plate 11with an outer plate 12 enclosing the saine.` One of the plates,

preferably the inner one 11, is rovided with projections 11 which may bel ormed by i'ndenting the same as previousl described'in.

relation to Fig. 6, so as to slig tly space the plates and formtherebetween a restricted chamber 13 for the refrigerant fluid. The rearend of the enclosure may be made also witha double wall but as amanufacturing expedient it is closed by a single plate14. The front endis o n for the insertion of receptacles or trays not shown) containingthe titions 15 and access is had to the o n front end of the element bya suitable c osare or.

plate 11 by oppositely bent portions 17 so as to provide spacedopeningsat the top of the trough to distribute the entering refrigerant fluid toboth sides of the element d. The out let connection f leads from vthetrp of element d as indicated. By constructing the freezing element d asa substantially total enclosure with thin slightly spaced walls themaximum of useful storage space is secured and black body conditions areclosely approximated.

While preferred forms of the invention have been herein shown anddescribed the invention is not limited to the specific details thereofbut covers all changes, modifications and adaptations within the scopeof the appended claims. L

I claim as myinvention:

1. In a mechanically o rated refrigerating outfit, a refrigerator avinga compartment for containing perishable articles, an extended evaporator`in'uiih'erllining at least a part of said compartment for containing avolatile liquid, and means for withdrawing the vapor of the liquid andcause said member to extract heat from said compart-l ment.

2. The combination with a compartment insulated a inst heat, of acontainer for volatile 'quid built into and formin apart ofthe lining ofsaid compartment, an means for inducing evaporation of the liquid insaid container to extract heat from said compartnient.

3. The combination with a compartment insulated against heat, of ametallic lining for said compartment, said linin forming one Wall of-anextended element or containing evaporating'liquid, and means forwithdrawing the vapor of said liquid thereby to extract heat from saidcom artmen-t.

4. The combination wit acom artmentfor erishable articles havinginsulating material gorming the inner portion of. the wall of thecompartment, of an evaporatng element im..- mediately adj aeent saidinsulation and forming a lining for said compartment, and means 'forinducin evaporation of a liquid contained in said element.

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y5. The combination with a compartment from which'heat is to beextracted, of an evaporator element presentinga lar'ge sur, face areawit-h'but small cubical content disposedjwithin said compartment seas toline a portion of the same and to extract heat therefrom both byradiation and convection, and means for inducing ,evaporation of aliquid contained in said element.

6. The combination with a compartment having its walls formed ofheatinsulating from said liquid.

- partment from which heat is to be extracted materlal, of a thinevaporator elementdisposed within said compartment adjacent said`heatinsulating material to form a liriing for at least one wall of thecompartment, and means for connecting said element to compressing andcondensing members to form' a closed cycle refrigerating system of therefrigerating apparatus connected to said element to form a closed cyclesystem.

8. In a refrigerating system, the combination with a heat-insulatingwall of a heatconducting plate adjacentsaid wall, means for maintaininga body of volatile liquid in a thin sheet or film between said wall andsald plate, and means'for' removing yvapor 9.A mechanical refrigeratorcomprising a motordr1ven compressor, a condenser, and

a hollow llining for said refrigerator, and

means for feeding liquid from said condenser into said linin compressor,sai lining being in direct contact with the interior of saidrefrigerator..l

10. In a closed cycle refrigerating system, a freezing compartment and arefriweratin'g compartment, and interconnected refrigerating elementsarranged to contain vaporizing refrigerant and to extract heat from saidcomartments, one of said elements forming at east a part of the liningof its compartment.'

11. In a closed cycle system, a freezing compartment and a refrigeratingcompartment,` refrigerating elements in said compartments arranged toline the same, said. elements being interconnected and each arranged tocontain vaporizing refrigerant.

12.. In a closed cycle system having a. plurality of compartments fromwhich heat is to Vbe extracted, an evaporator element in eachcompartment forming at least a part of the lining of the compartment,and means con- -necting said elements in series, and pressure reducingmeans connected to the last element-S in the series.

13. A `heat absorbing member fr refrigerating systems comprising anextended evaporator element arranged to fit withiny a comand to line aportion of the interior thereof, said element being constructed andarranged to dispose the liquid refrigerant in a thinv to be evaporatedby said film or sheet so. as to occupy a minimum amount of space withinthe compartment.

14. A heat absorbing member for refrigerating systems cmprising 'anextended evaporator element formed with a substantially plane facearranged to be disposed within a compartment from which heat is to beextracted so that said face forms the lining of atleast a part of thecompartment, said element being so thin as to provide merely a film ofevaporatingliquid in contact with said face. 1 5.'A refrigeratingelement comprising a pair of metallic sheets joined toeach otheradjacent their peripheries, one of said plates being indented to providecontact `projections for the other plateso as to maintain said platesslightly spaced throughout their full Aarea and provide a chambertherebetween of small volume.

16. A freezing element comprising a metallic container of such..proportions as to form a practically total enclosure of the black bodytype, means for maintaining a thin film ofliquid in contact with the eX-terior of said container, and means for inducing vapor-ization of theliquid.

17. freezing element comprising a container formed with hollow walls forcontaining a vaporizing refrigerant, saidcontainer having an outlet atthe top, and inlet means at thethottom of said element arranged to cfafect distribution of entering Huid.

18. A freezing element com'prisinga container formed with hollow wallsfor containing a vaporizing refrigerant, said container having an outletat the top, and means disbottoin thereof for distributirfg enteringfluid.

19. A freezing element comprising a container formed with hollow walls'for containing a vaporizing refrigerant, said container having an outletat the top, and means form- -ing a trough in the bottom of said elementfor effecting longitudinal and lateral distribution of entering fluid.

20. A freezing element comprising a con- 21. A freezing elementcomprising a container formed with hollow walls for containing avaporizing refrigerant', said container having an outlet at thetop,inlet means forming a troughdisposedlongitudinally and centrally beneathsaid-element, and a partila'lteral distribution of the entering fluid.

Signedy by'me at. Detroit, Wayne County, Michigan, this 26th dayofApril, 1926.

- RANSOM W. DAVENPORT.

.posed longitudinally of said element at-the tion within said trough foreffecting equal

